The circulatory system transports blood to deliver ... · Blood flow in the body • The blood moves from the left atrium into the left ventricle, which pumps the blood into the largest

The circulatory system transports blood to deliver important

substances, such as oxygen, to cells and to remove wastes, such

as carbon dioxide.

Section 1: Circulatory System

K

What I Know

W

What I Want to Find Out

L

What I Learned

Essential Questions

• What are the main functions of the circulatory system?

• How does the blood flow through the heart and body?

• What are the similarities and differences between the major components of

the blood?

Circulatory SystemCopyright © McGraw-Hill Education

Review

• muscle contraction

New

• artery

• capillary

• vein

• valve

• heart

• pacemaker

• plasma

• red blood cell

• platelet

• white blood cell

• atherosclerosis

Circulatory SystemCopyright © McGraw-Hill Education

Vocabulary

Circulatory SystemCopyright © McGraw-Hill Education

Functions of the Circulatory System

• Transports oxygen and nutrients

• Carries disease-fighting materials produced by the immune system

• Contains cell fragments and proteins for blood clotting

• Distributes heat throughout the body to help regulate body temperature

Circulatory SystemCopyright © McGraw-Hill Education

Blood Vessels

• Arteries

• Capillaries

• Veins

Structure of Blood Vessels

Animation

FPO

Add link to concepts in motion animation from page 993 here.

Circulatory SystemCopyright © McGraw-Hill Education

Circulatory SystemCopyright © McGraw-Hill Education

Blood Vessels

Arteries

• Oxygen-rich blood is carried away from

the heart in large blood vessels called

arteries.

• Arteries are composed of three layers:

• Outer layer of connective tissue

• Middle layer of smooth muscle

• Inner layer of endothelial tissue

Circulatory SystemCopyright © McGraw-Hill Education

Blood Vessels

Capillaries

• Microscopic blood vessels where the exchange of important substances and

wastes occur are capillaries.

• The walls are only one cell thick.

Circulatory SystemCopyright © McGraw-Hill Education

Blood Vessels

Veins

• The largest blood vessels are veins.

• Carry oxygen-poor blood back to the heart

• Contraction of skeletal muscles helps keep the blood moving.

• Valves are flaps of tissue that prevent blood from flowing backward.

Circulatory System

BrainPOP

FPO

Add link to concepts in motion animation from page 994 here.

Circulatory SystemCopyright © McGraw-Hill Education

Circulatory SystemCopyright © McGraw-Hill Education

The Heart

• A hollow, muscular organ that pumps blood throughout the body

• Pumps oxygenated blood to the body

• Pumps deoxygenated blood to the lungs

Circulatory SystemCopyright © McGraw-Hill Education

The Heart

Structure of the heart

• Divided into four compartments called chambers

• The right atrium and the left atrium receive blood returning to the heart.

• The right and left ventricles pump blood away from the heart.

• A strong muscular wall separates the left side of the heart from the right side of the heart.

• Valves separate the atria from the ventricles and keep blood flowing in one direction.

Circulatory SystemCopyright © McGraw-Hill Education

Circulatory SystemCopyright © McGraw-Hill Education

The Heart

How the heart beats

• The atria fill with blood.

• The atria contract, filling the ventricles

with blood.

• The sinoatrial (SA) node sends out

signals that cause both atria to

contract.

• The signal travels to another area in

the heart called the atrioventricular

node, causing both ventricles to

contract.

Circulatory SystemCopyright © McGraw-Hill Education

The Heart

How the heart beats

• Pulse

• The alternating expansion and relaxation of the artery wall caused by

contraction of the left ventricle

• Blood Pressure

• A measure of how much pressure is exerted against the vessel walls by

the blood

Blood Pressure

Virtual Lab

FPO

Add link to concepts in motion animation from page 994 here.

Circulatory SystemCopyright © McGraw-Hill Education

Circulatory SystemCopyright © McGraw-Hill Education

The Heart

Blood flow in the body

• Deoxygenated blood flows from the

right atrium into the right ventricle

and is pumped into the pulmonary

arteries that lead to the lungs.

• Oxygenated blood flows from the

lungs to the left atrium of the heart.

Circulatory SystemCopyright © McGraw-Hill Education

The Heart

Blood flow in the body

• The blood moves from the left atrium into the left ventricle, which pumps

the blood into the largest artery in the body, the aorta.

• Oxygen is released from the blood into the body cells by diffusion, and

carbon dioxide moves from the cells to the blood by diffusion.

The Circulatory System

Animation

FPO

Add link to concepts in motion animation from page 996 here.

Circulatory SystemCopyright © McGraw-Hill Education

Circulatory SystemCopyright © McGraw-Hill Education

Blood Components

Plasma

• The clear, yellowish portion of blood is the plasma.

• Carries glucose, fats, vitamins, minerals, hormones, and waste products

from the cells

Circulatory SystemCopyright © McGraw-Hill Education

Blood Components

Red Blood Cells

• Red blood cells carry oxygen to all of the body’s cells

• Consist of an iron-containing protein called hemoglobin

• Hemoglobin chemically binds with oxygen molecules and carries oxygen to

the body’s cells.

Circulatory SystemCopyright © McGraw-Hill Education

Blood Components

Platelets

• Cell fragments that are important in forming blood clots are platelets.

• Collect and stick to the vessel at the site of the wound

• Release chemicals that produce a protein called fibrin

• Fibrin is a protein that weaves a network of fibers across the cut that traps

blood platelets and red blood cells.

Circulatory SystemCopyright © McGraw-Hill Education

Blood Components

White Blood Cells

• The body’s disease fighters are the white blood cells, which are produced in

bone marrow.

• Recognize disease-causing organisms

• Produce chemicals to fight the invaders

• Surround and kill the invaders

Circulatory SystemCopyright © McGraw-Hill Education

Blood Groups

ABO blood group

• There are four types of blood—A, B, AB, and O.

Rh blood group

• Another marker found on the surface of red blood cells

Circulatory System Disorders

• Atherosclerosis is the condition of blocked arteries.

• When blood flow is reduced or blocked, the heart must work even harder to pump blood and vessels may burst.

Blood Types

Interactive Table

FPO

Add link to concepts in motion interactive table from page 998 here.

Circulatory SystemCopyright © McGraw-Hill Education

Circulatory SystemCopyright © McGraw-Hill Education

Review

Essential Questions

• What are the main functions of the circulatory system?

• How does the blood flow through the heart and body?

• What are the similarities and differences between the major components of

the blood?

Vocabulary

• artery

• capillary

• vein

• valve

• heart

• pacemaker

• plasma

• red blood cell

• platelet

• white blood cell

• atherosclerosis